<?php

/**
 * MigrateCommand class file.
 *
 * @author Qiang Xue <qiang.xue@gmail.com>
 * @link http://www.yiiframework.com/
 * @copyright Copyright &copy; 2008-2011 Yii Software LLC
 * @license http://www.yiiframework.com/license/
 */

/**
 * MigrateCommand manages the database migrations.
 *
 * The implementation of this command and other supporting classes referenced
 * the yii-dbmigrations extension ((https://github.com/pieterclaerhout/yii-dbmigrations),
 * authored by Pieter Claerhout.
 *
 * Since version 1.1.11 this command will exit with the following exit codes:
 * <ul>
 * <li>0 on success</li>
 * <li>1 on general error</li>
 * <li>2 on failed migration.</li>
 * </ul>
 *
 * @author Qiang Xue <qiang.xue@gmail.com>
 * @package system.cli.commands
 * @since 1.1.6
 */
class MigrateCommand extends CConsoleCommand {

    const BASE_MIGRATION = 'm000000_000000_base';

    /**
     * @var string the directory that stores the migrations. This must be specified
     * in terms of a path alias, and the corresponding directory must exist.
     * Defaults to 'application.migrations' (meaning 'protected/migrations').
     */
    public $migrationPath = 'application.migrations';

    /**
     * @var string the name of the table for keeping applied migration information.
     * This table will be automatically created if not exists. Defaults to 'tbl_migration'.
     * The table structure is: (version varchar(255) primary key, apply_time integer)
     */
    public $migrationTable = 'tbl_migration';

    /**
     * @var string the application component ID that specifies the database connection for
     * storing migration information. Defaults to 'db'.
     */
    public $connectionID = 'db';

    /**
     * @var string the path of the template file for generating new migrations. This
     * must be specified in terms of a path alias (e.g. application.migrations.template).
     * If not set, an internal template will be used.
     */
    public $templateFile;

    /**
     * @var string the default command action. It defaults to 'up'.
     */
    public $defaultAction = 'up';

    /**
     * @var boolean whether to execute the migration in an interactive mode. Defaults to true.
     * Set this to false when performing migration in a cron job or background process.
     */
    public $interactive = true;

    public function beforeAction($action, $params) {
        $path = Yii::getPathOfAlias($this->migrationPath);
        if ($path === false || !is_dir($path)) {
            echo 'Error: The migration directory does not exist: ' . $this->migrationPath . "\n";
            exit(1);
        }
        $this->migrationPath = $path;

        $yiiVersion = Yii::getVersion();
        echo "\nYii Migration Tool v1.0 (based on Yii v{$yiiVersion})\n\n";

        return parent::beforeAction($action, $params);
    }

    public function actionUp($args) {
        if (($migrations = $this->getNewMigrations()) === array()) {
            echo "No new migration found. Your system is up-to-date.\n";
            return 0;
        }

        $total = count($migrations);
        $step = isset($args[0]) ? (int) $args[0] : 0;
        if ($step > 0)
            $migrations = array_slice($migrations, 0, $step);

        $n = count($migrations);
        if ($n === $total)
            echo "Total $n new " . ($n === 1 ? 'migration' : 'migrations') . " to be applied:\n";
        else
            echo "Total $n out of $total new " . ($total === 1 ? 'migration' : 'migrations') . " to be applied:\n";

        foreach ($migrations as $migration)
            echo "    $migration\n";
        echo "\n";

        if ($this->confirm('Apply the above ' . ($n === 1 ? 'migration' : 'migrations') . "?")) {
            foreach ($migrations as $migration) {
                if ($this->migrateUp($migration) === false) {
                    echo "\nMigration failed. All later migrations are canceled.\n";
                    return 2;
                }
            }
            echo "\nMigrated up successfully.\n";
        }
    }

    public function actionDown($args) {
        $step = isset($args[0]) ? (int) $args[0] : 1;
        if ($step < 1) {
            echo "Error: The step parameter must be greater than 0.\n";
            return 1;
        }

        if (($migrations = $this->getMigrationHistory($step)) === array()) {
            echo "No migration has been done before.\n";
            return 0;
        }
        $migrations = array_keys($migrations);

        $n = count($migrations);
        echo "Total $n " . ($n === 1 ? 'migration' : 'migrations') . " to be reverted:\n";
        foreach ($migrations as $migration)
            echo "    $migration\n";
        echo "\n";

        if ($this->confirm('Revert the above ' . ($n === 1 ? 'migration' : 'migrations') . "?")) {
            foreach ($migrations as $migration) {
                if ($this->migrateDown($migration) === false) {
                    echo "\nMigration failed. All later migrations are canceled.\n";
                    return 2;
                }
            }
            echo "\nMigrated down successfully.\n";
        }
    }

    public function actionRedo($args) {
        $step = isset($args[0]) ? (int) $args[0] : 1;
        if ($step < 1) {
            echo "Error: The step parameter must be greater than 0.\n";
            return 1;
        }

        if (($migrations = $this->getMigrationHistory($step)) === array()) {
            echo "No migration has been done before.\n";
            return 0;
        }
        $migrations = array_keys($migrations);

        $n = count($migrations);
        echo "Total $n " . ($n === 1 ? 'migration' : 'migrations') . " to be redone:\n";
        foreach ($migrations as $migration)
            echo "    $migration\n";
        echo "\n";

        if ($this->confirm('Redo the above ' . ($n === 1 ? 'migration' : 'migrations') . "?")) {
            foreach ($migrations as $migration) {
                if ($this->migrateDown($migration) === false) {
                    echo "\nMigration failed. All later migrations are canceled.\n";
                    return 2;
                }
            }
            foreach (array_reverse($migrations) as $migration) {
                if ($this->migrateUp($migration) === false) {
                    echo "\nMigration failed. All later migrations are canceled.\n";
                    return 2;
                }
            }
            echo "\nMigration redone successfully.\n";
        }
    }

    public function actionTo($args) {
        if (isset($args[0]))
            $version = $args[0];
        else
            $this->usageError('Please specify which version to migrate to.');

        $originalVersion = $version;
        if (preg_match('/^m?(\d{6}_\d{6})(_.*?)?$/', $version, $matches))
            $version = 'm' . $matches[1];
        else {
            echo "Error: The version option must be either a timestamp (e.g. 101129_185401)\nor the full name of a migration (e.g. m101129_185401_create_user_table).\n";
            return 1;
        }

        // try migrate up
        $migrations = $this->getNewMigrations();
        foreach ($migrations as $i => $migration) {
            if (strpos($migration, $version . '_') === 0)
                return $this->actionUp(array($i + 1));
        }

        // try migrate down
        $migrations = array_keys($this->getMigrationHistory(-1));
        foreach ($migrations as $i => $migration) {
            if (strpos($migration, $version . '_') === 0) {
                if ($i === 0) {
                    echo "Already at '$originalVersion'. Nothing needs to be done.\n";
                    return 0;
                } else
                    return $this->actionDown(array($i));
            }
        }

        echo "Error: Unable to find the version '$originalVersion'.\n";
        return 1;
    }

    public function actionMark($args) {
        if (isset($args[0]))
            $version = $args[0];
        else
            $this->usageError('Please specify which version to mark to.');
        $originalVersion = $version;
        if (preg_match('/^m?(\d{6}_\d{6})(_.*?)?$/', $version, $matches))
            $version = 'm' . $matches[1];
        else {
            echo "Error: The version option must be either a timestamp (e.g. 101129_185401)\nor the full name of a migration (e.g. m101129_185401_create_user_table).\n";
            return 1;
        }

        $db = $this->getDbConnection();

        // try mark up
        $migrations = $this->getNewMigrations();
        foreach ($migrations as $i => $migration) {
            if (strpos($migration, $version . '_') === 0) {
                if ($this->confirm("Set migration history at $originalVersion?")) {
                    $command = $db->createCommand();
                    for ($j = 0; $j <= $i; ++$j) {
                        $command->insert($this->migrationTable, array(
                            'version' => $migrations[$j],
                            'apply_time' => time(),
                        ));
                    }
                    echo "The migration history is set at $originalVersion.\nNo actual migration was performed.\n";
                }
                return 0;
            }
        }

        // try mark down
        $migrations = array_keys($this->getMigrationHistory(-1));
        foreach ($migrations as $i => $migration) {
            if (strpos($migration, $version . '_') === 0) {
                if ($i === 0)
                    echo "Already at '$originalVersion'. Nothing needs to be done.\n";
                else {
                    if ($this->confirm("Set migration history at $originalVersion?")) {
                        $command = $db->createCommand();
                        for ($j = 0; $j < $i; ++$j)
                            $command->delete($this->migrationTable, $db->quoteColumnName('version') . '=:version', array(':version' => $migrations[$j]));
                        echo "The migration history is set at $originalVersion.\nNo actual migration was performed.\n";
                    }
                }
                return 0;
            }
        }

        echo "Error: Unable to find the version '$originalVersion'.\n";
        return 1;
    }

    public function actionHistory($args) {
        $limit = isset($args[0]) ? (int) $args[0] : -1;
        $migrations = $this->getMigrationHistory($limit);
        if ($migrations === array())
            echo "No migration has been done before.\n";
        else {
            $n = count($migrations);
            if ($limit > 0)
                echo "Showing the last $n applied " . ($n === 1 ? 'migration' : 'migrations') . ":\n";
            else
                echo "Total $n " . ($n === 1 ? 'migration has' : 'migrations have') . " been applied before:\n";
            foreach ($migrations as $version => $time)
                echo "    (" . date('Y-m-d H:i:s', $time) . ') ' . $version . "\n";
        }
    }

    public function actionNew($args) {
        $limit = isset($args[0]) ? (int) $args[0] : -1;
        $migrations = $this->getNewMigrations();
        if ($migrations === array())
            echo "No new migrations found. Your system is up-to-date.\n";
        else {
            $n = count($migrations);
            if ($limit > 0 && $n > $limit) {
                $migrations = array_slice($migrations, 0, $limit);
                echo "Showing $limit out of $n new " . ($n === 1 ? 'migration' : 'migrations') . ":\n";
            } else
                echo "Found $n new " . ($n === 1 ? 'migration' : 'migrations') . ":\n";

            foreach ($migrations as $migration)
                echo "    " . $migration . "\n";
        }
    }

    public function actionCreate($args) {
        if (isset($args[0]))
            $name = $args[0];
        else
            $this->usageError('Please provide the name of the new migration.');

        if (!preg_match('/^\w+$/', $name)) {
            echo "Error: The name of the migration must contain letters, digits and/or underscore characters only.\n";
            return 1;
        }

        $name = 'm' . gmdate('ymd_His') . '_' . $name;
        $content = strtr($this->getTemplate(), array('{ClassName}' => $name));
        $file = $this->migrationPath . DIRECTORY_SEPARATOR . $name . '.php';

        if ($this->confirm("Create new migration '$file'?")) {
            file_put_contents($file, $content);
            echo "New migration created successfully.\n";
        }
    }

    public function confirm($message, $default = false) {
        if (!$this->interactive)
            return true;
        return parent::confirm($message, $default);
    }

    protected function migrateUp($class) {
        if ($class === self::BASE_MIGRATION)
            return;

        echo "*** applying $class\n";
        $start = microtime(true);
        $migration = $this->instantiateMigration($class);
        if ($migration->up() !== false) {
            $this->getDbConnection()->createCommand()->insert($this->migrationTable, array(
                'version' => $class,
                'apply_time' => time(),
            ));
            $time = microtime(true) - $start;
            echo "*** applied $class (time: " . sprintf("%.3f", $time) . "s)\n\n";
        } else {
            $time = microtime(true) - $start;
            echo "*** failed to apply $class (time: " . sprintf("%.3f", $time) . "s)\n\n";
            return false;
        }
    }

    protected function migrateDown($class) {
        if ($class === self::BASE_MIGRATION)
            return;

        echo "*** reverting $class\n";
        $start = microtime(true);
        $migration = $this->instantiateMigration($class);
        if ($migration->down() !== false) {
            $db = $this->getDbConnection();
            $db->createCommand()->delete($this->migrationTable, $db->quoteColumnName('version') . '=:version', array(':version' => $class));
            $time = microtime(true) - $start;
            echo "*** reverted $class (time: " . sprintf("%.3f", $time) . "s)\n\n";
        } else {
            $time = microtime(true) - $start;
            echo "*** failed to revert $class (time: " . sprintf("%.3f", $time) . "s)\n\n";
            return false;
        }
    }

    protected function instantiateMigration($class) {
        $file = $this->migrationPath . DIRECTORY_SEPARATOR . $class . '.php';
        require_once($file);
        $migration = new $class;
        $migration->setDbConnection($this->getDbConnection());
        return $migration;
    }

    /**
     * @var CDbConnection
     */
    private $_db;

    protected function getDbConnection() {
        if ($this->_db !== null)
            return $this->_db;
        elseif (($this->_db = Yii::app()->getComponent($this->connectionID)) instanceof CDbConnection)
            return $this->_db;

        echo "Error: CMigrationCommand.connectionID '{$this->connectionID}' is invalid. Please make sure it refers to the ID of a CDbConnection application component.\n";
        exit(1);
    }

    protected function getMigrationHistory($limit) {
        $db = $this->getDbConnection();
        if ($db->schema->getTable($this->migrationTable) === null) {
            $this->createMigrationHistoryTable();
        }
        return CHtml::listData($db->createCommand()
                                ->select('version, apply_time')
                                ->from($this->migrationTable)
                                ->order('version DESC')
                                ->limit($limit)
                                ->queryAll(), 'version', 'apply_time');
    }

    protected function createMigrationHistoryTable() {
        $db = $this->getDbConnection();
        echo 'Creating migration history table "' . $this->migrationTable . '"...';
        $db->createCommand()->createTable($this->migrationTable, array(
            'version' => 'string NOT NULL PRIMARY KEY',
            'apply_time' => 'integer',
        ));
        $db->createCommand()->insert($this->migrationTable, array(
            'version' => self::BASE_MIGRATION,
            'apply_time' => time(),
        ));
        echo "done.\n";
    }

    protected function getNewMigrations() {
        $applied = array();
        foreach ($this->getMigrationHistory(-1) as $version => $time)
            $applied[substr($version, 1, 13)] = true;

        $migrations = array();
        $handle = opendir($this->migrationPath);
        while (($file = readdir($handle)) !== false) {
            if ($file === '.' || $file === '..')
                continue;
            $path = $this->migrationPath . DIRECTORY_SEPARATOR . $file;
            if (preg_match('/^(m(\d{6}_\d{6})_.*?)\.php$/', $file, $matches) && is_file($path) && !isset($applied[$matches[2]]))
                $migrations[] = $matches[1];
        }
        closedir($handle);
        sort($migrations);
        return $migrations;
    }

    public function getHelp() {
        return <<<EOD
USAGE
  yiic migrate [action] [parameter]

DESCRIPTION
  This command provides support for database migrations. The optional
  'action' parameter specifies which specific migration task to perform.
  It can take these values: up, down, to, create, history, new, mark.
  If the 'action' parameter is not given, it defaults to 'up'.
  Each action takes different parameters. Their usage can be found in
  the following examples.

EXAMPLES
 * yiic migrate
   Applies ALL new migrations. This is equivalent to 'yiic migrate up'.

 * yiic migrate create create_user_table
   Creates a new migration named 'create_user_table'.

 * yiic migrate up 3
   Applies the next 3 new migrations.

 * yiic migrate down
   Reverts the last applied migration.

 * yiic migrate down 3
   Reverts the last 3 applied migrations.

 * yiic migrate to 101129_185401
   Migrates up or down to version 101129_185401.

 * yiic migrate mark 101129_185401
   Modifies the migration history up or down to version 101129_185401.
   No actual migration will be performed.

 * yiic migrate history
   Shows all previously applied migration information.

 * yiic migrate history 10
   Shows the last 10 applied migrations.

 * yiic migrate new
   Shows all new migrations.

 * yiic migrate new 10
   Shows the next 10 migrations that have not been applied.

EOD;
    }

    protected function getTemplate() {
        if ($this->templateFile !== null)
            return file_get_contents(Yii::getPathOfAlias($this->templateFile) . '.php');
        else
            return <<<EOD
<?php

class {ClassName} extends CDbMigration
{
	public function up()
	{
	}

	public function down()
	{
		echo "{ClassName} does not support migration down.\\n";
		return false;
	}

	/*
	// Use safeUp/safeDown to do migration with transaction
	public function safeUp()
	{
	}

	public function safeDown()
	{
	}
	*/
}
EOD;
    }

}
